The <canvas> element is not natively supported by the backend formatting engine. However, what can be done is to replace the <canvas> with an image in the print <div> before sending to the formatter. There are a few Javascript drawn <canvas> elements on this page. They are processed to the output by the xepOnine.jgPlugin.js Javascript by converting them on-the-fly to image format.
This is a second <canvas> element on the page:
Dolor in ut sit nulla exerci kasd magna elit stet nulla dolor erat aliquip duo tincidunt nonumy duo. Stet elitr no justo diam duis facer eum kasd ipsum quis id diam. Sed takimata tempor sit tempor at stet diam ut sanctus clita nulla duo sadipscing lorem eirmod tempor. Exerci clita quis consetetur elitr elitr. Illum duo ea lorem dolore et eirmod aliquam gubergren velit dolore magna nonumy consequat sea takimata ut vulputate lorem. Vulputate rebum magna sea eos clita sanctus et diam in ut wisi augue nibh odio takimata lorem diam. Diam vero nonumy tation dolor in.